Many liquid products are traditionally delivered to the consumer in relatively large containers. These traditional containers require the consumer to manually measure out a specific volume of the liquid product for use. The consumer generally measures out an identical quantity of liquid product each time the product is used. Thus, the consumer is required to successively, manually measure out a uniform volume of liquid product from the container. This manual operation, however is time consuming and messy. Moreover, performing this operation manually frequently results in inaccurate measuring. Since the efficacy of products often depends upon how accurately the liquid product volume is measured, manual measuring risks inaccuracy and failure to obtain optimal efficacy.
U.S. Pat. No. 3,288,335 issued to Steffens et al., on Nov. 29, 1966, discloses a multi-chambered tubular metering device for insertion into the opening of liquid containers. Theoretically, as the container is tipped, a volume of liquid is metered by controlling the venting of air into the container. The container becomes airlocked when the desired volume is metered.
In practice, however, it has been found that there is difficulty ensuring that the container becomes airlocked when the container is tilted at relatively low dispensing angles. At these low angles it is quite possible the container will not become airlocked. This allows liquid to flow continuously from the container. Consequently, the device fails to meter and dispense a uniform volume of liquid.
U.S. Pat. No. 4,449,651 issued to Roder, deceased et al. on May 22, 1984, discloses a metering device with concentric chambers that also operates by controlling the venting of air. A metering device of this configuration is costly and complex to manufacture. In addition, and like the device of Steffens et al., it occupies an excessive volume within the container. This excessive volume is undesirable when marketing liquid products. If the metering device occupies excessive volume within the container, then the container dimensions must be enlarged to house the same amount of liquid product. Enlarging the container increases materials and, consequently, costs.
It is an object of the invention to provide a metering device which will accurately dispense successive uniform doses, without continuously flowing.
It is also an object of the invention to provide a metering device of reduced overall volume for a given uniform liquid product volume.
It is additionally an object of the invention to encourage the end user to tilt the container in a direction which ensures proper operation of the metering device.
It is likewise an object of the invention to accomplish the foregoing while reducing the overall costs involved.
The aforementioned and other objects of the invention will become more apparent hereinafter.